Impact of scalar mesons on the rare B-decays

2015 ◽  
Vol 39 ◽  
pp. 1560086
Author(s):  
Aidos Issadykov ◽  
Mikhail A. Ivanov ◽  
Sayabek K. Sakhiyev

In the wake of exploring uncertainty in the full angular distribution of the [Formula: see text] caused by the presence of the intermediate scalar [Formula: see text] meson, we perform the straightforward calculation of the [Formula: see text] (S is a scalar meson) transition form factors in the full kinematical region within the covariant quark model. We restrict ourselves by the scalar mesons below 1 GeV: [Formula: see text]. As an application of the obtained results we calculate the widths of the semileptonic and rare decays [Formula: see text], [Formula: see text] and [Formula: see text]. We compare our results with those obtained in other approaches.

2019 ◽  
Vol 204 ◽  
pp. 08003 ◽  
Author(s):  
Aidos Issadykov

We evaluate Bs → K*0 transition form factors in the full kinematical region within the covariant confined quark model. The calculated form factors can be used to calculate the Bs → K*0 μ+μ– rare decay branching ratio, which was recently measured by LHCb collaboration.


2020 ◽  
Vol 241 ◽  
pp. 02007
Author(s):  
G. Ramalho

We present calculations of γ*N → N* transition form factors, where N is the nucleon and N* is a nucleon resonance, based on a covariant quark model. Our main focus is at high photon virtualities (large Q2) where the valence quark degrees of freedom dominate the contributions to the transition form factors and helicity amplitudes. In that regime, the quark model estimates can be compared with the available data, particularly with the Jefferson Lab data at intermediate and large momentum transfer (Q2 > 2 GeV2). The main focus is on the Δ(1232)3/2+, N(1440)1/2+, N(1535)1/2- and N(1520)3/2- resonances, but estimates for other higher mass resonances are also discussed.


2005 ◽  
Vol 20 (08n09) ◽  
pp. 1785-1790 ◽  
Author(s):  
D. O. RISKA

The chiral quark model posits that pions couple to the axial current of constituent quarks. This chiral pion coupling governs the pion decays of baryon resonances and also implies pion and multipion interactions between the quarks. The qualitative features of this model for the description of pionic decay widths and baryon spectra are outlined. When the covariant quark model wave function for the nucleon is chosen so as to describe the empirical nucleon form factors the pion decay widths of the positive parity resonances are underpredicted. This indicates the presence of significant multiquark components in these resonances.


2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Yu-Kuo Hsiao ◽  
Ling Yang ◽  
Chong-Chung Lih ◽  
Shang-Yuu Tsai

AbstractMore than ten $$\Omega _c^0$$ Ω c 0 weak decay modes have been measured with the branching fractions relative to that of $$\Omega ^0_c\rightarrow \Omega ^-\pi ^+$$ Ω c 0 → Ω - π + . In order to extract the absolute branching fractions, the study of $$\Omega ^0_c\rightarrow \Omega ^-\pi ^+$$ Ω c 0 → Ω - π + is needed. In this work, we predict $${{\mathcal {B}}}_\pi \equiv {{\mathcal {B}}}(\Omega _c^0\rightarrow \Omega ^-\pi ^+)=(5.1\pm 0.7)\times 10^{-3}$$ B π ≡ B ( Ω c 0 → Ω - π + ) = ( 5.1 ± 0.7 ) × 10 - 3 with the $$\Omega _c^0\rightarrow \Omega ^-$$ Ω c 0 → Ω - transition form factors calculated in the light-front quark model. We also predict $${{\mathcal {B}}}_\rho \equiv {{\mathcal {B}}}(\Omega _c^0\rightarrow \Omega ^-\rho ^+)=(14.4\pm 0.4)\times 10^{-3}$$ B ρ ≡ B ( Ω c 0 → Ω - ρ + ) = ( 14.4 ± 0.4 ) × 10 - 3 and $${{\mathcal {B}}}_e\equiv {{\mathcal {B}}}(\Omega _c^0\rightarrow \Omega ^-e^+\nu _e)=(5.4\pm 0.2)\times 10^{-3}$$ B e ≡ B ( Ω c 0 → Ω - e + ν e ) = ( 5.4 ± 0.2 ) × 10 - 3 . The previous values for $${{\mathcal {B}}}_\rho /{{\mathcal {B}}}_\pi $$ B ρ / B π have been found to deviate from the most recent observation. Nonetheless, our $${{\mathcal {B}}}_\rho /{{\mathcal {B}}}_\pi =2.8\pm 0.4$$ B ρ / B π = 2.8 ± 0.4 is able to alleviate the deviation. Moreover, we obtain $${{\mathcal {B}}}_e/{{\mathcal {B}}}_\pi =1.1\pm 0.2$$ B e / B π = 1.1 ± 0.2 , which is consistent with the current data.


2015 ◽  
Vol 39 ◽  
pp. 1560113
Author(s):  
A. Liptaj ◽  
S. Dubnička ◽  
A. Z. Dubničková ◽  
M. A. Ivanov

The covariant quark model with infrared confinement (CQM) is a well-suited theoretical framework to describe large variety of hadronic processes, including rare decays of heavy mesons. In this text we focus on the reactions [Formula: see text], which have been recently measured by Refs. 1–4. The measurements include also information about the angular distributions and their significance is given by possible New Physics (NP) effects which are predicted in numerous beyond Standard Model (SM) scenarios. Even with clever choice of experimental observables, a model dependence cannot be fully removed from the theoretical predictions. In this text we present the computation of the [Formula: see text] form factors within the CQM and give results for some of the most commonly used observables ([Formula: see text], [Formula: see text]).


1995 ◽  
Vol 359 (1-2) ◽  
pp. 1-7 ◽  
Author(s):  
F. Cardarelli ◽  
I.L. Grach ◽  
I.M. Narodetskii ◽  
G. Salmé ◽  
S. Simula

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